Business number vs corporation number: these two get mixed up constantly, partly because they sound alike and partly because a corporation has both. If you have ever stared at a government letter wondering which number they actually want, this is for you.
The short version
A corporation number identifies your corporation with the body that incorporated it. It is about your company's existence as a legal entity. A business number identifies your business with the Canada Revenue Agency for tax purposes. It is about how you deal with the CRA.
They come from different places, they do different jobs, and a corporation ends up with both. A sole proprietorship, by contrast, has no corporation number at all, because it is not a corporation.
The corporation number
When you incorporate, the government that registers you, either Corporations Canada federally or a provincial registry like Ontario's, assigns your corporation a number. This is your corporation number.
If you incorporated federally, it is typically a seven-digit number. Provincial corporation numbers vary in format. You will see this number on your certificate of incorporation and your articles. You use it when you file your annual return with that registry, make changes to your corporation, or need to prove the company exists and is in good standing.
The business number
The business number, or BN, comes from the CRA. It is a nine-digit number that acts as the single identifier for all your dealings with the federal tax system. What makes the BN slightly confusing is that it is the root of several different program accounts. The nine digits are your core BN, and then the CRA tacks on a two-letter code and four digits for each type of account you open:
- RT for GST/HST
- RP for payroll
- RC for corporate income tax
- RM for import/export
So one business number might have several accounts hanging off it, each with the same nine-digit base. When the CRA asks for your business number, they usually mean those core nine digits.
Why a corporation has both
When you incorporate, you get a corporation number from the registry. Separately, you get a business number from the CRA so you can pay corporate tax, collect GST/HST, and run payroll. They are not interchangeable. The registry does not care about your BN. The CRA does not care about your corporation number. Each wants its own.
A sole proprietor skips the corporation number entirely. They are not incorporated, so there is nothing for a registry to number. But they will still get a business number from the CRA the moment they register for GST/HST or payroll.
How to find each one
Your corporation number is on your certificate of incorporation and your articles. If you have lost them, you can find it through the registry that incorporated you, federal or provincial, using your corporation's name. Your business number is on most CRA correspondence, in your CRA My Business Account, and on your GST/HST and payroll documents. If you genuinely cannot find it, the CRA can give it to you over the phone after they confirm your identity.
When it matters
For day-to-day operating, you rarely think about either one. They matter at specific moments: filing annual returns, dealing with the CRA, opening a business bank account, applying for financing, or proving your corporation is real and in good standing.
When you incorporate with Korporex, your articles, CRA business number, and minute book are set up together, so your corporation number and business number are both in place from the start.